A Comparison between Coronal and Axial Scans in PNS CT

BACKGROUND AND OBJECTIVES: A coronal section computerized tomography (CT) is essential for the diagnosis of paranasal sinusitis, especially in the evaluation of the ostiomeatal unit. Although the coronal scan is preferred to the axial scan, the role of the axial scan during endoscopic sinus surgery has not been thoroughly examined. The aim of this study is to compare the advantages and disadvantages of coronal and axial scans in the paranasal sinuses. MATERIALS AND METHODS: Selected for study were the coronal and axial scans of 30 preoperative sinus CTs showing minimal sinus pathology. The rates of detecting 15 anatomic structures in the coronal and axial sections were analyzed across 60 sides. RESULTS: The coronal scan was superior to the axial scan in detecting eight normal structures, including the anterior ethmoid artery, the opening of the maxillary sinus and the superior meatus (p<0.05). The axial scan was useful in showing the vertical portion of the 3rd basal lamella and the opening and the anterior wall of the sphenoid sinus (p<0.05). CONCLUSION: The coronal scan is more informative than the axial scan but has limitations in showing the structures lying on the coronal plane. The axial scan plays a complementary role in covering this limitation. Together, the coronal and axial sections of a sinus CT can help the surgeon to understand the three dimensional structure of the paranasal sinus before endoscopic sinus surgery.

The Value of CT Coronal Scan in Diagnosis of Invasion of Skull Base by Nasopharyngeal Carcinoma / 实用放射学杂志

Objective To evaluate the value of CT coronal scan in diagnosis of invasion of skull base by nasopharyngeal carcinoma(NPC).Methods The status of the skull base of 186 cases with NPC showed by CT coronal and axial scan was analyzed retrospectively,these cases were proved by pathology.Results In the 186 cases of NPC,the invasion of the base of skull wasn't revealed in 98 cases(52.7%)by CT coronal and axial scan.CT coronal scan showed bone invasion in 5 cases(2.7%),while the invasion wasn't recognized by axial scan.By CT coronal scan,the invasion of skull base was confirmed in 9 and excluded in 16 of 25 cases(13.4%)in which the invasion was uncertain by axial scan.Wider and deeper invasion was recognized in 23 cases(12.3%) by coronal scan,though obvious invasion had been diagnosed after axial scan.Accordant invasion was displayed in 35 cases(18.8%) by CT coronal and axial scan.Conclusion CT coronal scan is valuable for demonstrating whether the base of skull is invaded or not and the position,range and degree of the invasion.Only by combining CT axial with coronal scan a complete and objective conclusion can be drawn.